Electrometer is an electrical instrument for measuring the static electricity potential. The electrometer can be divided into two categories: contact electrometer and non-contact electrometer. Compared with the contact electrometer, the non-contact electrometer based on the principle of electrostatic induction is less influenced by input capacitance and input resistance. The measurement accuracy of a non-contact electrometer is better than a contact electrometer. However, the non-contact electrometer can not be used to monitor the static electricity potential for the test value of the non-contact electrometer will decay exponentially with time.
What is needed, therefore, is to provide an electrometer to monitor the static electricity potential.